In general, toilets, washstands and sinks are designed to discharge foreign matters out when water is drained. Moreover, because a part to drain water adopts a U-shaped trap structure in order to prevent a bad smell from backing up, such a trap structure causes pipe blockage. In addition to such a structural reason, of course, pipes of the toilets, washstands and sinks are frequently blocked by relatively large-sized foreign matters.
Now, various devices for clearing blockage of a pipe come on the market, but it is difficult to effectively clear the blockage using such devices. The difficulty in effectively clearing the blocked pipe using the conventional devices may be caused by that sufficient shock or pressure is not applied to the blocked part. For instance, when a predetermined pressure is applied from the outside to the inside of a toilet in a bathroom, the conventional devices do not provide sufficient airtightness between the outside and the inside of the toilet and cannot effectively generate or transfer pressure to the pipe connected from the inside of the toilet.